<template>
   
  <view>
     
   <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
       <!-- 左侧的滚动视图区域 -->
            <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
              <block v-for="(item, i) in cateList" :key="i">
                 <view :class="['left-scroll-view-item',i==active ? 'active' :'' ]" @click = 'activeChange(i)'>{{item.cat_name}}</view>
               </block>
            </scroll-view>
           <!-- 右侧的滚动视图区域 -->
           <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop" >
             <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
               <view class="cate-lv2-title">| {{item2.cat_name}} |</view>
               <!-- 动态渲染三级分类的列表数据 -->
               <view class="cate-lv3-list">
                 <!-- 三级分类 Item 项 -->
                 <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                   <!-- 图片 -->
                   <image :src="item3.cat_icon"></image>
                   <!-- 文本 -->
                   <text>{{item3.cat_name}}</text>
                 </view>
               </view>
             </view>
           </scroll-view>
    </view>
  </view>
</template>

<script>
    // 导入自己封装的 mixin 模块
    import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
      // 将 badgeMix 混入到当前的页面中进行使用
        mixins: [badgeMix],
    data() {
      return {
        wh:0,
        active:0,   
        cateList: [],
          // 二级分类数据
        cateLevel2:[],
        // 滚动条距离顶部的距离
        scrollTop: 0
       
      };
    },
   onLoad() {
      this.getCateList()
     const sysInfo = uni.getSystemInfoSync()
     // 可用高度 = 屏幕高度 - navigationBar高度 - tabBar高度 - 自定义的search组件高度
      this.wh = sysInfo.windowHeight - 50 
     
    },
    methods: {
      async getCateList() {
        // 发起请求
        const { data: res } = await uni.$http.get('/api/public/v1/categories')
        // 判断是否获取失败
        if (res.meta.status !== 200) return uni.$showMsg()
        // 转存数据
        this.cateList = res.message
        // console.log(this.cateList);
        this.cateLevel2 = res.message[0].children
       
      },
      activeChange(i){
        this.active = i 
        // 让 scrollTop 的值在 0 与 1 之间切换
         this.scrollTop = this.scrollTop === 0 ? 1 : 0
         console.log(this.scrollTop);
       this.cateLevel2 = this.cateList[i].children
        // console.log(this.cateLevel2 );
      },
      // 点击三级分类项跳转到商品列表页面
      gotoGoodsList(item3) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      },
        
      gotoSearch() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
      
    }
  }
  
</script>

<style lang="scss">
    .scroll-view-container{
      display:flex;
      .left-scroll-view{
        width:120px;
        text-align:center;
            
          .left-scroll-view-item{
            background-color:#F7F7F7;
            height: 50px;
            line-height:50px;
            font-size: 13px;
            font-weihgt:blod;
            position: relative;
              
          // 激活项的样式
              &.active {
                background-color: #ffffff;
                position: relative;
        
                // 渲染激活项左侧的红色指示边线
                &::before {
                  content: ' ';
                  display: block;
                  width: 3px;
                  height: 100%;
                  background-color: #c00000;
                  position: absolute;
                  left: 0;
                 
                }
              }
          }
           
      }
   
    }
    .cate-lv2-title {
      font-size: 12px;
      font-weight: bold;
      text-align: center;
      padding: 15px 0;
      background-color:#F7F7F7;
    }
    .cate-lv3-list {
      display: flex;
      flex-wrap: wrap;
    
      .cate-lv3-item {
        width: 33.33%;
        margin-bottom: 10px;
        display: flex;
        flex-direction: column;
        align-items: center;
    
        image {
          width: 60px;
          height: 60px;
        }
    
        text {
          font-size: 12px;
        }
      }
    }
</style>
